Printing press margin bar



March 30, 1937. H. A. w. WOOD PRINTING PRESS MARGIN BAR Original Filed Opt. 4, 1932 2 Sheets-Sheet l Mmh so, 1937. H: A. w. WOOD 2,075,562

PRINTING PRESS MARGIN BAR Original Filed om. 4, 1952 2 Sheets-Sheet 2 J27 dezar 7 zgmy/fziz q Patented Mar. 30, 1937 UNITED STATES PRINTING PRESS MARGINBAR Application. October 4, 1932,.Serial No. 636,099 Renewed December 6, .1934.

5 Claims.

This invention relates to that type of means for holding down printing plates on their cylinders which act along the straight sides of the plates.

The principal object of the invention is to provide a means for clamping a plate along its straight sides in which the clamping means is made movable in an axial direction with respect to the plate, so that the plate may be removed more easily than heretofore, and so that any 10 inaccuracies in the plate may easily be accommodated by the movable margin bar, and to provide surfaces in the plate cylinder cooperating with the margin bar of such a nature that when one end clamp has been opened all the margin bars affecting the plates clamped by that clamp are moved longitudinally on an incline to relieve the pressure of the margin bars against the ledges carried by the plate and the closing of the end clamp will lower the side clamps and. lock the plates.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which 25 Fig. 1 is a plan of a plate clamping means constructed in accordance with this invention and applied to a typical plate cylinder;

Fig. 2 is a longitudinal sectional view on the line 22 of. Fig. 1, showing the position of the parts with the plates clamped;

Fig. 3 is a similar view showing the position of the parts with the plates unclamped;

Fig. 4 is a sectional view on the line 4--4 of Fig. 2;

Fig. 5 is a sectional view on the line 5-5 of Fig.

Fig. 6 is a plan of one of the margin bars, as shown in Fig. 4, and

Fig. 7 is a sectional view as indicated by the 40 line I in Fig. 6.

The invention is shown as being applied to a plate cylinder I having the usual end clamps 2 and 2*, center ring 3 and center clips 4 for securing the plates P on the cylinder. The print- 45 ing plates P are provided with outwardly projecting straight ledges 5 on their straight sides. These ledges are designed to cooperate with T- shaped margin bars 6 and 1, two of which are shown. Each clamping mechanism embodies 50 two of these margin bars in the preferred form. These margin bars are located in a longitudinal slot 8 in the cylinder I, there being preferably such a slot diametrically opposite the one shown and a second complete clamping mechanism be- 55 ing located therein.

The, margin bars, 6- and- 1' are normally forced to the leftas viewediinFig. 1 by springs 9 and I0 respectively; These springsbear against abutments H' whichzare'securedlto the plate cylinder. The marginbars'are adapted to bemoved .to the right by the use of a connecting rod l2, supplied with jam nuts I3, adjustable connecting link It, rod l5 and jam nuts l6. On the outside end of the rod I2 2. projecting piece I! is secured by nuts l8 which is moved to the right by either end 10 clamp 2 or 2 when that clamp is moved back to release the plates.

Means is provided whereby the motion of the end clamps 2 or 2 to the right for the purpose of releasing them raises the margin bar outwardly in the cylinder, that is, releases them. The contrary motion to the left clamps them down against the ledges of the printing plate. In the form shown this lifting action is provided for by making the bottom edge of each mar- 20 gin bar slanting and by providing corresponding slanting surfaces 2| on outwardly extending projections 22 in the bottom of the slot 8. The locking action is secured by providing correspondingly slanting surfaces 23 and 24 on the bar and 25 the cylinder. It will be seen readily that the motion of these margin bars to the right necessarily forces them upwardly to relieve the ledges 5 on the plates while motion to the left clamps the edges of the plates down.

It is to be understood that the slot 8 is duplicated on the other side of the cylinder, preferably in a diametrical opposite position, and corresponding mechanism is provided on the other side. Thus a cylinder carrying two semi-cylindrical plates is provided with this device for holding down the edges of the plates on both sides of the cylinder. The operator of one end clamp releases or looks up the straight edges of two printing plates.

By this invention means is provided for holding down the straight sides of the printing plate with additional means for releasing the clamping bars in cooperation with clamps on the curved edges of the plate.

It will be understood, of course, that the inclined bevels 20, 2|, 23 and 24 do not have to be located in the particular places shown but could be replaced by a similar bevel on the edge of the printing plate. In this case the margin bars would move on a line parallel to the central axis of the cylinder and their under sides which bear on the inclined edge of the plate would be inclined at the same angle.

Although I have illustrated and described only one fonn of the invention I am aware of the fact that modifications can be made therein by any person skilled in the art without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited in this respect otherwise than as set forth in the claims, but what I do claim is:

1. The combination with a printing plate cylinder and a movable margin bar having two opposite means along its sides for engaging ledges on two printing plates and provided with surfaces underneath which slant longitudinally, of printing plates on opposite sides of the margin bar having side ledges adapted to be engaged by said means on the margin bar and means whereby, when the margin bar is moved longitudinally on the cylinder, it will be raised or lowered thereby to release or clamp down the straight edges of the plate.

2. The combination with a plate cylinder, of an end plate clamp movable longitudinally of the cylinder, a margin bar between the straight edges of two adjacent printing plates on the cylinder, the margin bar having a longitudinally 25 slanting bottom and side projections having correspondingly slanted upper surfaces, the cylinder having correspondingly slanting surfaces engaging the slanting surfaces on the bar, and means connected with the end clamp for moving the margin bar longitudinally.

3. In a plate clamping device, the combination with means for clamping the curved edges of the plate, of movable means for clamping the straight edges of the plate and means for operating the second named clamping means from the first.

4. In a plate clamping device, the combination with an end clamp for clamping the curved edge of the plate, of means for clamping and unclamping the straight edge of the plate, and means for operating the first named means from said clamp.

5. The combination with a plate cylinder and its longitudinal movable margin bar, arranged to clamp and unclamp a plate at its straight edge and a clamp for the curved edge of the plate, of means operated by said clamp for moving said .margin bar longitudinally of the cylinder to thereby clamp and unclamp the straight edge of the plate.

HENRY A. WISE WOOD. 

